Animation of a flight through Saturn's cloudtops, showing its huge ring system stretching across the sky. The view then moves away to show the planet in space. Saturn's rings extend from some 7000 kilometres above the equator to more than 80, 000km. They are made up of countless particles of water ice ranging from dust grain-size to large boulders. Despite their great extent, the rings are extremely thin, being less than a kilometre deep and in most places much less. Saturn's atmosphere is mostly hydrogen with a small amount of helium, and traces of gases including ammonia and light hydrocarbons.